- DIMERIC MURRAYAFOLINE A, A POTENTIAL BIS-CARBAZOLE ALKALOID: 'BIOMIMETIC' SYNTHESIS, ATROPOISOMER SEPARATION, AND ANTIMALARIAL ACTIVITY
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The first total synthesis of a (potential) dimeric carbazole alkaloid is described.After an improved preparation of the monomeric building block, 'biomimetic dimerization' by oxidative phenolic coupling was best achieved with di-tert-butyl peroxide in chlorobenzene, leading to a highly selective formation of the 2,2'-coupled 'dimer', the parent framework of several naturally occurring dimeric carbazole alkaloids.For the atropoenantiomer analysis, a chromatographic procedure on chiral phase was developed.Both the mono- and the dimeric phenolic carbazoles displayed in vitro antimalarial activity against Plasmodium falciparum.
- Bringmann, Gerhard,Ledermann, Alfons,Francois, Guido
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- Total synthesis of clausamine e and furanoclausamine B
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4-Bromo-1-methoxycarbazole-3-carboxylate has been synthesized by a sequence of benzannulation-decarboxylation-bromination, and utilized as a common intermediate for the first total synthesis of clausamine E and the second synthesis of furanoclausamine B. Heck coupling and Br-Li exchange reactions are, respectively, employed as the key steps.
- Mal, Dipakranjan,Roy, Joyeeta
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- New syntheses of murrayafoline-A and murrayaquinone-A via Fischer indolization of 2-sulfonyloxyphenylhydrazone (Fischer indolization and its related compounds. Part 29)
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Two carbazole alkaloids, murrayafoline-A (4a) and murrayaquinone-A (4b), were synthesized from 1, 2, 3, 4-tetrahydro-8-methanesulfonyloxy-6- methylcarbazole (8) prepared in the application of Fischer indolization of 2- sulfonyloxyphenylhydrazone.
- Murakami, Yasuoki,Yokoo, Hiroshi,Watanabe, Toshiko
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- Total synthesis of carbazole alkaloids
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A Suzuki-Miyaura cross coupling, followed by triphenylphosphine mediated Cadogan reductive cyclization sequence provided efficient access to a series of carbazole alkaloids. In the present work, this approach was applied to the total synthesis of mukonine, clauszoline K, koenoline, murrayanine, murrayafoline A, mukoeic acid, glycoborine, glycozolicine, mukolidine, mukoline, glycozoline, 3-methoxy-9H-carbazole-1-carboxylic acid methyl ester, (3-methoxy-9H-carbazol-1-yl)-methanol, 3-methoxy-9H-carbazole-1-carbaldehyde, 3-methoxy-9H-carbazole-1-carboxylic acid, 2-methyl-9H-carbazole and nonsteroidal anti-inflammatory drug (NSAID) carprofen and its derivatives.
- Bhatthula, Bharath kumar goud,Kanchani, Janardhan reddy,Arava, Veera reddy,Subha
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p. 874 - 887
(2019/01/11)
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- Palladium-Catalyzed Regioselective Synthesis of 1-Hydroxycarbazoles Under Aerobic Conditions
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A palladium-catalyzed aerobic C?H amidation of N-Ts-2-amino-3′-hydroxylbiaryls has been developed to afford a diverse range of 1-hydroxycarbazoles with high regioselectivity and efficiency. This protocol benefits from operational simplicity, robustness, a
- Youn, So Won,Kim, Young Ho,Jo, Yoon Hyung
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p. 462 - 468
(2019/01/04)
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- "on Water" Promoted Ullmann-Type C-N Bond-Forming Reactions: Application to Carbazole Alkaloids by Selective N-Arylation of Aminophenols
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The Ullmann-type cross coupling of a variety of aromatic, aliphatic amines with aryl halides is reported using a CuI-based catalytic system in combination with an easily accessible prolinamide ligand in aqueous media. The method is mild and tolerant to air, moisture, and a wide range of functional groups, providing a novel way to access a variety of aminated products. Secondary amines like heteroaromatic amines and nucleobases have also been used, affording the corresponding coupling products in good to excellent yields. Moreover, this method has been employed for chemoselective C-N arylation of aminophenols and further utilized for the synthesis of carbazole natural products, avoiding the protection and deprotection steps.
- Chakraborti, Gargi,Paladhi, Sushovan,Mandal, Tirtha,Dash, Jyotirmayee
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p. 7347 - 7359
(2018/07/29)
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- Synthesis of Methylene-Bridged Biscarbazole Alkaloids by using an Ullmann-type Coupling: First Total Synthesis of Murrastifoline-C and Murrafoline-E
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We describe the total synthesis of methylene-bridged biscarbazole alkaloids by using a late-stage Ullmann-type coupling of fully functionalised carbazole subunits. The carbazole derivatives were synthesised via a sequence of palladium(0)- and palladium(II
- Kutz, Sebastian K.,B?rger, Carsten,Schmidt, Arndt W.,Kn?lker, Hans-Joachim
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p. 2487 - 2500
(2016/02/14)
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- First total synthesis of murrastifoline B and an improved route to murrastifoline F
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We report the first total synthesis of murrastifoline B and an improved route to murrastifoline F using a twofold palladium-catalyzed Buchwald-Hartwig amination as key step. The monomeric carbazole and the biaryl precursor are also prepared via palladium-
- B?rger, Carsten,Schmidt, Arndt W.,Kn?lker, Hans-Joachim
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p. 1381 - 1384
(2014/06/23)
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- Iodine-catalyzed aromatization of tetrahydrocarbazoles and its utility in the synthesis of glycozoline and murrayafoline A: A combined experimental and computational investigation
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A new protocol for the aromatization of tetrahydrocarbazoles has been achieved using a catalytic amount of iodine, giving high yields. The role of iodine in the aromatization has been explained by DFT, and its wide scope is extended to the total synthesis of glycozoline and murrayafoline A. This method has proven to be tolerant of a broad range of functional groups. This journal is the Partner Organisations 2014.
- Humne, Vivek,Dangat, Yuvraj,Vanka, Kumar,Lokhande, Pradeep
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supporting information
p. 4832 - 4836
(2014/07/07)
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- A Pd-catalyzed cascade reaction of N-H insertion and oxidative dehydrogenative aromatization: A new entry to 2-amino-phenols
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A palladium-catalyzed cascade reaction of N-H insertion (NHI) and oxidative dehydrogenative aromatization (ODA) has been developed, which affords a straightforward and efficient way to access the carbazole precursors (2-arylamino-phenols) as well as to prepare 2-alkylamino-phenols from non-aromatic substrates. This journal is the Partner Organisations 2014.
- Ding, Dong,Lv, Xiaobing,Li, Jian,Qiu, Lin,Xu, Guangyang,Sun, Jiangtao
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p. 4084 - 4088
(2014/06/10)
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- Copper-catalyzed N=H insertion and oxidative aromatization cascade: Facile synthesis of 2-arylaminophenols
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A copper-catalyzed cascade reaction of N-H insertion and oxidative aromatization has been developed. 2-Arylaminophenols have been prepared in moderate to high yields from the diazo substrates. Moreover, this newly established methodology allows efficient access to natural 1-oxygenated carbazole alkaloids, such as glycozolicine and murrayafoline A. Copper falls: A copper-catalyzed cascade reaction of N=H insertion and oxidative aromatization yields 2-arylaminophenols. This newly established methodology also allows efficient access to natural 1-oxygenated carbazole alkaloids, such as glycozolicine and murrayafoline A.
- Ding, Dong,Lv, Xiaobing,Li, Jian,Xu, Guangyang,Ma, Bing,Sun, Jiangtao
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p. 1539 - 1542
(2014/06/09)
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- Transition metals in organic synthesis. Part 108: First total synthesis of ekeberginine
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Using a palladium(II)-catalyzed oxidative cyclization and a regioselective nickel-mediated prenylation as key steps, the first total synthesis of the 1-oxygenated carbazole alkaloid ekeberginine has been achieved in six steps and in 63% overall yield.
- Thomas, Claudia,Kn?lker, Hans-Joachim
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p. 591 - 593
(2013/02/23)
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- A tandem reduction-oxidation protocol for the conversion of 1-keto-1,2,3,4-tetrahydrocarbazoles to carbazoles via tosylhydrazones through microwave assistance: Efficient synthesis of glycozoline, clausenalene, glycozolicine, and deoxycarbazomycin B and the total synthesis of murrayafoline A
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A novel and efficient methodology for the synthesis of carbazoles from 1-keto-1,2,3,4-tetrahydrocarbazoles via the corresponding tosylsulfonhydrazones by a one-pot tandem reduction-oxidation protocol using a combination of NaBH4 and Pd-C on MgSO4·7H2O, a solid support, under microwave is developed. The reaction is successfully extended toward the synthesis of several naturally occurring carbazole alkaloids, namely 3-methylcarbazole, glycozoline, clausenalene, glycozolicine, murrayafoline A, and deoxycarbazomycin B, a carbazole derivative that is known to have a promising antimicrobial activity.
- Chakraborty, Suchandra,Chattopadhyay, Gautam,Saha, Chandan
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- Direct amination of phenols under metal-free conditions
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Herein, we disclose the metal-free synthesis of arylamines via the direct amination of phenols using aminating reagents. This reaction procedure uses easy accessible aminating reagents and provides a versatile synthetic route to a broad range of arylamines with various functionalities in good to excellent yield. By using a two-step route of amination and oxidative coupling reaction, we synthesized three naturally occurring carbazole alkaloids: murrayafoline A, mukonine, and clausenine from two commercially available phenols. Georg Thieme Verlag Stuttgart · New York.
- Yu, Jianzhong,Wang, Yongtao,Zhang, Peizhi,Wu, Jun
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supporting information
p. 1448 - 1454
(2013/07/26)
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- Novel approach to biscarbazole alkaloids via Ullmann coupling - Synthesis of murrastifoline - A and bismurrayafoline - A
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Unprecedented Ullmann couplings of murrayafoline-A with either 6-bromo- or 4-bromocarbazole derivatives provide highly efficient synthetic routes to the biscarbazole alkaloids murrastifoline-A (6 steps, 66% overall yield) and bismurrayafoline-A (6 steps, 28% overall yield).
- B?rger, Carsten,Kataeva, Olga,Kn?lker, Hans-Joachim
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p. 7269 - 7273
(2012/10/07)
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- Palladium-catalyzed direct arylation-based domino synthesis of annulated N-heterocycles using alkenyl or (hetero)aryl 1,2-dihalides
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A palladium-catalyzed reaction sequence consisting of an intermolecular amination and an intramolecular direct arylation enabled highly regioselective syntheses of functionalized indoles or carbazoles and proved to be amenable to the use of inexpensive 1,2dichloroarenes as electrophiles.
- Ackermann, Lutz,Althammer, Andreas,Mayer, Peter
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experimental part
p. 3493 - 3503
(2010/02/28)
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- Acid-free synthesis of carbazoles and carbazolequinones by intramolecular Pd-catalyzed, microwave-assisted oxidative biaryl coupling reactions efficient syntheses of murrayafoline A, 2-methoxy-3-methylcarbazole, and glycozolidine
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A mild and. efficient methodology for the synthesis of oxygenated. carbazoles from diarylamines under non-acidic conditions was developed, based on a palladium-catalyzed, microwave-assisted double C-H bond activation process. This new protocol was successfully applied to the synthesis of three naturally occurring carbazoles, namely murrayafoline A, 2-methoxy-3-methylcarbazole, and glycozolidine. The scope of the reaction was also expanded, to include the synthesis of benzo fused carbazolequinones. Wiley-VCH Verlag GmbH & Co. KGaA.
- Sridharan, Vellaisamy,Antonia Martin,Carlos Menendez
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supporting information; experimental part
p. 4614 - 4621
(2009/12/05)
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- Intramolecular Pd(II)-catalyzed oxidative biaryl synthesis under air: Reaction development and scope
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(Figure Presented) New reaction conditions for intramolecular palladium(II)-catalyzed oxidative carbon-carbon bond formation under air are described. The use of pivalic acid as the reaction solvent, instead of acetic acid, results in greater reproducibility, higher yields, and broader scope. This includes the use of electron-rich diarylamines as illustrated in the synthesis of three naturally occurring carbazole products: Murrayafoline A, Mukonine, and Clausenine. A variety of side products have also been isolated, casting light on competing reaction pathways and revealing new reactivity with palladium(II) catalysis.
- Liegault, Benoit,Lee, Doris,Huestis, Malcolm P.,Stuart, David R.,Fagnou, Keith
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p. 5022 - 5028
(2008/09/21)
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- Domino N-H/C-H bond activation: Palladium-catalyzed synthesis of annulated heterocycles using dichloro(hetero)arenes
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(Chemical Equation Presented) One after the other: A novel palladium-catalyzed domino reaction consisting of an amination and a direct C-H bond arylation allows for a general synthesis of annulated heterocycles starting from readily available 1,2-dichloroarenes and primary as well as secondary anilines (see scheme; Cy = cyclohexyl). This is high-lighted by an efficient synthesis of the natural product murrayafoline A.
- Ackermann, Lutz,Althammer, Andreas
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p. 1627 - 1629
(2008/02/13)
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- Anionic [4+2] cycloaddition strategy in the regiospecific synthesis of carbazoles: formal synthesis of ellipticine and murrayaquinone A
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Anionic [4+2] cycloaddition of furoindolones (e.g., 7 and 10) has been developed as an effective means to the synthesis of carbazoles. This reaction has been shown to be feasible with a wide variety of Michael acceptors to give carbazoles and fused carbaz
- Mal, Dipakranjan,Senapati, Bidyut Kumar,Pahari, Pallab
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p. 3768 - 3781
(2008/02/01)
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- Synthesis of oxygenated carbazoles by palladium-mediated oxidative double C-H activation of diarylamines assisted by microwave irradiation
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Microwave irradiation in the presence of palladium acetate and traces of dimethylformamide allows the fast and efficient cyclodehydrogenation of diphenylamines into carbazoles. The scope of the microwave-assisted reaction is broader than that of the one using conventional conditions in that it allows the preparation of oxygenated carbazoles without apparent loss in yield. The applicability of the method to the preparation of carbazole alkaloids has been demonstrated by the development of a total synthesis of murrayafoline A, which proceeds in 50% overall yield from commercially available materials and is the shortest and most efficient route for the preparation of this alkaloid to date. Georg Thieme Verlag Stuttgart.
- Sridharan, Vellaisamy,Martín, Ma. Antonia,Menéndez, J. Carlos
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p. 2375 - 2378
(2008/02/09)
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- Regioselective synthesis of 1-hydroxycarbazoles via anionic [4+2] cycloaddition of furoindolones: A short synthesis of murrayafoline-A
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Suitably N-protected furoindolones react regioselectively with a variety of Michael acceptors in the presence of LDA to give 1-hydroxycarbazoles in a single-pot process and in good yields. The methodology has been applied to the synthesis of murrayafoline
- Mal,Senapati,Pahari
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p. 1071 - 1075
(2007/10/03)
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- Total synthesis of the natural carbazoles Murrayanine and Murrayafoline A, based on the regioselective Diels-Alder addition of exo-2-oxazolidinone dienes
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A new synthesis of the natural carbazoles Murrayanine (1) and Murrayafoline A (3) is described. The key step in the synthetic route involved the regioselective cycloaddition of the diene 4,5-dimethylene-3-phenyl-1,3- oxazolidin-2-one (4) to acrolein (6) c
- Benavides, Adriana,Peralta, Javier,Delgado, Francisco,Tamariz, Joaquin
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p. 2499 - 2504
(2007/10/03)
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- Synthesis of carbazoles from N-(N,N-diarylamino)phthalimides with aluminum chloride via diarylnitrenium ions
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Generation of diarylnitrenium ions from N-(N,N-diarylamino)phthalimides by treatment with AlCl3 in benzene or in 1,2-dichloroethane leads to formation of carbazoles by intramolecular C-C bond formation. The reaction proceeds in synthetically useful yields.
- Kikugawa,Aoki,Sakamoto
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p. 8612 - 8615
(2007/10/03)
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- Synthesis of methylene-bridged binary carbazole alkaloids and a related tricarbazole
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The first synthesis of the methylene-bridged binary carbazole alkaloids bismurrayafoline-A and chrestifoline-A is described. As an interesting side product, a likewise benzylically connected trimer was identified, a potential natural product.
- Bringmann, Gerhard,Tasler, Stefan
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p. 2337 - 2343
(2007/10/03)
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- Synthesis of mukonine and seven further 1-oxygenated carbazole alkaloids
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As an intermediate in the synthesis of seven further 1-oxygenated 3- C1-substituted carbazole alkaloids, mukonine (1) was synthesized in 46% overall yield, starting from indole-3-carbaldehyde (12) with a Horner-Emmons reaction as the crucial st
- Bringmann, Gerhard,Tasler, Stefan,Endress, Heike,Peters, Karl,Peters, Eva-Maria
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p. 1501 - 1505
(2007/10/03)
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- Transition metal-diene complexes in organic synthesis - 16.1 Iron-mediated total synthesis of 1-oxygenated carbazole alkaloids
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Using a methodology of consecutive iron-induced C - C and C - N bond formation we describe the total synthesis of murrayafoline A, murrayaquinone A, koenoline, murrayanine, mukoeic acid, and mukonine.
- Knoelker, Hans-Joachim,Bauermeister, Michael
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p. 11221 - 11236
(2007/10/02)
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- A NEW ROUTE TO 1-OXYGENATED CARBAZOLES. SYNTHESIS OF THE CARBAZOLE ALKALOIDS MURRAYAFOLINE-A AND MURRAYAQUINONE-A
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1-Oxygenated carbazoles are prepared in 4 steps from indole-2-carboxylates by condensation with γ-butyrolactones to give the lactones (12), followed by hydrolysis with concomitant decarboxylation to the alcohols (13), and oxidation to the aldehydes (14).The aldehydes (14) cyclise to 1-methoxycarbazoles on treatment with boron trifluoride-methanol or with methanolic hydrogen chloride.The methoxycarbazoles (15a) and (4) were converted into the corresponding carbazolequinones (18) and (7) by demethylation, and oxidation.The carbazole alkaloids murrayafoline-A (4) and murrayaquinone-A (7) were prepared.
- Martin, Tracey,Moody, Christopher J.
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p. 235 - 240
(2007/10/02)
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- A NEW ROUTE TO 1-OXYGENATED CARBAZOLES. SYNTHESIS OF MURRAYAFOLINE-A
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1-Oxygenated carbazoles are prepared in four steps from indole-2-carboxylates by Claisen condensation with butyrolactones, followed by hydrolysis with concomitant decarboxylation, oxidation, and ring closure (Scheme 2); the route is applied to the synthes
- Martin, Tracey,MoodY, Christopher J.
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p. 5841 - 5842
(2007/10/02)
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- BISMURRAYAFOLINE-A AND -B, TWO NOVEL "DIMERIC" CARBAZOLE ALKALOIDS FROM MURRAYA EUCHRESTIFOLIA
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The structures of bismurrayafoline-A (1) and -B (5), the first and the second naturally occurring "dimeric" carbazole alkaloids isolated from Murraya euchrestifolia Hayata (Rutaceae) have been determined by spectral and chemical experiments.KEYWORDS - bismurrayafoline-A; bismurrayafoline-B; Murraya euchrestifolia; Rutaceae; carbazole alkaloid; murrayafoline-A; murrayafoline-B
- Furukawa, Hiroshi,Wu, Tian-Shung,Ohta, Tomoko
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p. 4202 - 4205
(2007/10/02)
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